People gather on the Mall to watch Pope Francis’s address to Congress on Thursday. (Matt McClain/The Washington Post)

On Thursday, Pope Francis became the first pontiff to address a joint meeting of Congress. While he touched on many contentious issue during his address, including the death penalty, climate change, income inequality and partisan polarization, he devoted a particularly large amount of time to discussing the nation’s treatment of its 11 million undocumented immigrants. The pope strongly encouraged Americans to remember their immigrant roots, to feel empathy for the plight of the undocumented and to resist the urge to resolve immigration problems through deportation:

We, the people of this continent, are not fearful of foreigners, because most of us were once foreigners. I say this to you as the son of immigrants, knowing that so many of you are also descended from immigrants . . . We must not be taken aback by their numbers, but rather view them as persons, seeing their faces and listening to their stories, trying to respond as best we can to their situation. To respond in a way which is always humane, just and fraternal. We need to avoid a common temptation nowadays: to discard whatever proves troublesome.

With 163 members of Congress affiliated with the Catholic Church and nearly 50 million Catholics in the country, the pope is uniquely positioned to shape the future of American immigration policy. So does the pope actually have the power to persuade his parishioners on immigration?

Our recent research into clergy leadership on immigration reform offers clues about the likely consequences of the pope’s comments on public opinion. Our findings suggest that Catholic leaders may actually struggle to persuade the public.

In 2012, we conducted an experiment within a survey, the Cooperative Congressional Election Study, that randomly exposed some of our Catholic respondents to a fictitious USA Today article describing Catholic Archbishop Timothy Dolan’s testimony before the House Judiciary subcommittee on immigration policy and enforcement. Using language very similar that of Francis, the article quoted Dolan as saying, “Immigration is ultimately a humanitarian issue since it impacts the basic rights and dignity of millions of persons and their families. Our immigration system fails to meet the moral test of protecting the basic rights and dignity of the human person.”

The article then explained that Dolan and the Church believe undocumented immigrants come to the United States to “reconnect with family members or find work” and not for some “nefarious purpose.” The fictitious report also attributed to Dolan a policy proposal for a “a six- to nine-month grace period” for undocumented immigrants to “come forward to register, to agree to pay fines and back taxes, to learn English, and to go to the back of the line.” The article ended with Dolan being quoted as saying that members of Congress “should not forget the teachings of Leviticus 19:34” — which states that “the alien who resides among you shall be to you as the citizen among you; you shall love the alien as yourself, for you were aliens in the land of Egypt.”

Although Catholics have a well-documented history of following their clergy’s lead on political issues, we found that Catholics, regardless of their religiosity, were largely unmoved by what Dolan said to Congress. Catholics’ opinions about immigration reform and undocumented immigrants were not influenced in any discernible way by exposure to Dolan’s message, as the graph below shows:

We conducted a similar experiment among Methodists, Southern Baptists and members of the Evangelical Lutheran Church in America. Despite the fact that lay Catholics are thought to follow their church’s leaders more than Protestants follow Protestant leaders, we found the opposite: Methodists, Southern Baptists and Lutherans became more favorable to immigration when exposed to pro-immigration messages attributed to their denomination’s leadership. In other words, Catholics were uniquely resistant to clergy leadership on immigration.

So what can we say about the likely effect of the pope’s historic remarks to Congress? Earlier this week, David Buckley relied on a recent YouGov study to argue that the “Pope can change Catholics’ minds about the culture war.” Our older data about a much different issue — immigration — force us to reach a distinct conclusion about papal influence. As our experiments show, lay Catholics were not persuaded by a strikingly similar message delivered in a strikingly similar venue from an only slightly less distinguished church leader.

Our study, of course, is not a perfect analog for what happened on Thursday, and there is a chance that the pope’s very real 2015 speech to a joint meeting of Congress will carry more weight with American Catholics than the highly artificial 2012 committee testimony we attributed to Dolan. One particularly important difference in this regard is that while Dolan was embroiled in a scandal in the months before our experiment, Francis’s approval rating among Catholics tops 90 percent.

Still, our findings suggest that the pope’s compassion for undocumented immigrants may fall on deaf ears. His address to Congress may end up much like the president’s addresses to Congress: They generate a lot of attention but only a tiny amount of change.

Kevin Wallsten is an associate professor in the Department of Political Science at California State University at Long Beach. Tatishe Nteta is an associate professor in the Department of Political Science at the University of Massachusetts at Amherst.